LM309K STEEL 5V 1A Voltage Regulator TO-3
The LM309K is a classic, easy-to-use 5-volt regulator designed for local regulation on digital logic cards, such as those using TTL logic. Housed in a robust TO-3 steel power package, it is capable of delivering a consistent output current in excess of 1 ampere to a load. This component effectively solves the problems associated with single-point power regulation by allowing you to place the regulator directly on the circuit board where the power is needed, ensuring stable and noise-free voltage distribution.
This regulator is built to be exceptionally durable and user-friendly. It is essentially blowout-proof, featuring internal current limiting to protect against excessive output current and thermal shutdown that activates if the IC begins to overheat, safeguarding the device and the load. A key advantage of the LM309K is its stability and simplicity; it requires no external components for basic operation, though an input bypass capacitor is recommended if the regulator is far from the main power supply filter. While designed as a fixed 5V regulator, its output can be adjusted to higher voltages with external circuitry, leveraging its excellent current-handling and thermal protection features.
Features:
- Designed for local regulation on digital logic cards.
- Internal thermal overload protection for device safety.
- Internal current limiting protects against short circuits.
- No external components required for basic operation.
- Excellent rejection of load and line transients.
- Available in a rugged, high-power TO-3 steel package.
- Simple and straightforward to implement in a circuit.
Specifications:
| Parameter | Conditions | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Output Voltage | Tj=25∘C | 4.8 | 5.05 | 5.2 | V |
| Line Regulation | Tj=25∘C,7.0V≤VIN≤25V | – | 4.0 | 50 | mV |
| Load Regulation | Tj=25∘C,5mA≤IOUT≤1.5A | – | 15 | 100 | mV |
| Quiescent Current | 7.4V≤VIN≤25V | – | 5.2 | 10 | mA |
| Ripple Rejection | Tj=25∘C | – | 50 | – | dB |
| Output Noise Voltage | TA=25∘C,10Hz≤f≤100kHz | – | 40 | – | μV |
| Thermal Resistance (Junction to Case) | – | 2.5 | – | ||
| Input Voltage (Max) | – | – | 35 |
Pinout:
| Pin | Description |
|---|---|
| Case | Output |
| Pin 1 | Input |
| Pin 2 | Ground |
Applications:
- On-card regulation for TTL and DTL logic circuits.
- Local 5V power supply for mixed-signal systems.
- General-purpose +5V power source for hobbyist and industrial electronics.
- Post-regulation for switching power supplies.
- Constant current regulator (with external components).
Packages Included:
- 1x LM309K STEEL 5V 1A Voltage Regulator TO-3.
